Winter Houseplant Care
Don’t Fight the Cold
When temperatures drop outside and your nesting instinct kicks in, don’t fight it! It’s time to head in and give those houseplants a little TLC. You can avoid frostbite and still get your gardening fix by providing routine care and attending to the “deferred maintenance” of those tender tropicals that share your living space.
Your houseplants that spent the summer outdoors should have moved back in by now, and may be in quarantine for a short time to ensure they are pest free before introducing them to those that were inside the whole time. After a week or so in isolation, check each plant thoroughly so that one-by-one you can place them in their winter homes. I like to do any pruning, repotting and spraying of these before they come indoors, but if you haven’t done it yet now is the time. In addition to maintaining a workable size, a good haircut will help your plants adapt to the lower indoor light by letting the light penetrate into the interior foliage.
Another important project that you should do periodically is a detailed inspection of each plant that stays indoors year round. These plants are easy to overlook until a problem becomes obvious, at which time it may be too late to fix. Make it a habit to really look closely at each plant once every few weeks. Look throughout the foliage (top and bottom) and along the stems for bugs, or signs of bugs. Also note the color of the leaves, check for spots, drying or off-color. Is the plant getting leggy? Does the bark look healthy? How does the soil look and feel (coarse and moist, fine and dusty, etc.)?
A few common issues that may arise include bug infestation, worn out potting soil and leggy plants. The treatments for these, if caught early on, are relatively simple. Plan ahead for these issues by keeping a few supplies on hand including potting soil, horticultural oil, a clean and sharp pair of pruners and a few old newspapers. At the first sign of a bug infestation, do a treatment. Most bugs will be susceptible to horticultural oil because it is not a poison, but kills by smothering. It is also effective against eggs, which is not true of many poisons. Simply take the plant outdoors and spray the whole plant, top and bottom of the leaves, and the soil surface. If the weather is too cold, you can spray indoors but take care to protect against overspray as this stuff is slick on floors and can make a mess of furniture and countertops. In the case of whitefly use sticky traps (similar to flypaper) as well as the horticultural oil application.
The fix for worn out potting soil is repotting. Remove the plant from the pot, loosen the roots a bit, gently knock off the bad soil, and place back in the old container with good soil. Be sure to plant it high enough in the pot, so that the top of the root mass is about an inch below the pot lip. This allows for watering and root growth as well. Sometimes a newly repotted plant will need to be staked. Texture is the dead giveaway for soil condition. Good potting soil includes coarse organic matter, and usually perlite. When it is worn out, the soil particles are very fine and do not retain or drain moisture properly, in really advanced situations the plant will sit much lower in the container and the soil may have shrunken from the sides of the pot. Purchase high quality potting soil for the longest interval between repottings.
Leggy plants may be just overgrown, or they could be suffering from a lack of light. Either way, they need to be cut back a bit. If the leaves are pale and somewhat elongated, the plant should be moved to a brighter location. Another symptom of not enough light is thinness of the foliage. If you have no more light to give, consider adding a full-spectrum fluorescent lamp as a supplement.
As a rule, houseplants respond to winter light conditions by slowing down. This is particularly true if you keep the temperature in your home below seventy degrees. While they will perform best with some supplemental ambient humidity, it is a good idea to allow soil to get a little dry between waterings. Also you can cut back a bit on fertilization in winter, to between half and three-fourths the warm weather rate. Boost humidity by keeping plants in groups and running a cool vaporizer periodically. Keep plants away from heat vents. Make your winter warm and bright by gardening indoors in the glow of your grow light, and enjoy your winter greenery.